Prodrive BCS: Myths vs Fact

[bugblatterbeast]

Aboslutely none

 

except for the case where one wants to run a very low wastegate setting and have the option to push up boost (for example 8-9psi with just the actuator and 20+ lbs under computer control. the stock high-detonation map is mapped for around 9 psi). with the stock solenoid, you are forced to trade-off transient performance against range of control.

[LittleBlueGT]

Guys:

 

I am using a DB 20G with AVO TMIC and WI. If I am not having any problems hitting boost with the stock BCS, are there any significant advantages for me to switch to a Prodrive BCS?

 

I have to almost agree with rao. I tuned my car with both. There are some advantages to tuning with the pro-drive EBCS, but I think some others here are magnifying the highlights.

 

I am sure with careful tuning of the TD tables one can get the boost to ramp up a bit quicker from WG spring value to target boost, but that is about it.

[Infamous1]

Of course this is all assumming the WGDC values are not near maxed out to hit the target values.

[05pearl]

The wastegate spring on my DB 20g is 10lb (did not want to use the 15lb spring becuase I wanted to go down to 10lb if WI safety ever kicked on). I peak at about 19psi (at 5500'). If I can't spool up noticeably faster with the Prodrive, then it sounds like it is not worth the effort to change out and tune for it.

[mickeyd2005]

In my limited experience, I've found that using a 1.0 mm pill with the stock BCS is just as effective as the Prodrive BCS. It is also not as sensitive to small changes in WGDC. 1.0 mm is also not excessively small that it prevents fast inflation of the actuator chamber. It just seems easier to tune plus it is a lot less money.

[SeeeeeYa]

In my limited experience, I've found that using a 1.0 mm pill with the stock BCS is just as effective as the Prodrive BCS. It is also not as sensitive to small changes in WGDC. 1.0 mm is also not excessively small that it prevents fast inflation of the actuator chamber. It just seems easier to tune plus it is a lot less money.

 

Contrary to what I found, but then I didn't know as much about TD when I was doing my smaller pill experiments. I will say this, however, that switching from the stock BCS to the Prodrive BCS cured all my boost tuning problems at the time and was infinitely easier to get the results I wanted.

 

Mostly, bbb said it best. With the Prodrive I find no compromises or tradeoffs. Tuning WGDC is logical and straightforward. As for saving money.......... my time and frustration was worth the small $$, but seriously, after what it costs to properly install a larger turbo the Prodrive is a pittance.

 

I can see keeping the stock BCS if you still have the VF40 and are conservative about boost limits.

 

Rao and LBGT have more experience and better tuning skills than I do, so I guess I have to consider I may be missing something since they don't see the Prodrive as superior like I do.

[mickeyd2005]

The 2 port BCS with smaller pill gives the same spool up characteristic as the BCS if tuned correctly.

 

My theory is that most people do not give WGDC enough headroom for TD proportional to keep the wastegate fully closed during spoolup. The higher sensitivity of the 3 port needs less headroom so it makes it appear that the 3 port is improving spool.

 

All I know is that you can get really good spoolup if your WGDC is in the 40-70% range. If it is in the 80-90% range, the WGDC is bumping into max and will not be able to fully keep the wastegate closed during spoolup.

[LittleBlueGT]

All I know is that you can get really good spoolup if your WGDC is in the 40-70% range. If it is in the 80-90% range, the WGDC is bumping into max and will not be able to fully keep the wastegate closed during spoolup.

 

Can you explain this?

 

How can "bumping into max" not keep it fully closed?

[mickeyd2005]

If it takes 90% WGDC to hit target boost and keep it stable at target boost then 90% WGDC will not keep the wastegate fully closed.

[LittleBlueGT]

If it takes 90% WGDC to hit target boost and keep it stable at target boost then 90% WGDC will not keep the wastegate fully closed.

 

 

I get it. I thought it was just using 90% WGDC to spool it.

[SeeeeeYa]

The 2 port BCS with smaller pill gives the same spool up characteristic as the BCS if tuned correctly.

 

My theory is that most people do not give WGDC enough headroom for TD proportional to keep the wastegate fully closed during spoolup. The higher sensitivity of the 3 port needs less headroom so it makes it appear that the 3 port is improving spool.

 

All I know is that you can get really good spoolup if your WGDC is in the 40-70% range. If it is in the 80-90% range, the WGDC is bumping into max and will not be able to fully keep the wastegate closed during spoolup.

 

See, this is what I'm saying, I HAD to use almost max WGDC values to reach the boost targets I wanted when I had the VF40. Then after I installed the Prodrive the WGDC fell to around 50% and I had some control again.

 

My AVO380 boost targets are 22.5 tapering to 19 at 7k with WGDC around 60% falling off to 45% after 6k. Since I already had the Prodrive, DW injectors, and AVO pump installed when I put the turbo in I had no reason to "try" the stock BCS. I still question why anyone would, really.

 

It just seems to me that the Prodrive's dynamics enable better WG actuation, period. There is much lower resistance in the WG fill circuit without a pill which leads me to think the Prodrive will be better at capping boost without overshoot, especially during the end of spoolup when larger WGDC have been speced. At least that is how I explain my lack of overshoot . It is also why I used the ID hoses I did, larger for the compressor to the BCS and smaller from the WGA to the BCS.

 

I admit not trying the pill thing with the Prodrive..... along with much further tuning lately. Mother Nature has been having winter fun here for a while now. But I will, just so I know what it does. In a sense it is just like using a smaller pill with the stock BCS, and while I liked some things that did, I did NOT like others.

 

Like I said, all my information comes from just this one car, and my own limited experience tuning. I'm still learning and read these threads hoping to learn more. The reason my WB got permanently installed was because I can never leave the tune alone .

[LittleBlueGT]

See, this is what I'm saying, I HAD to use almost max WGDC values to reach the boost targets I wanted when I had the VF40. Then after I installed the Prodrive the WGDC fell to around 50% and I had some control again.

 

My AVO380 boost targets are 22.5 tapering to 19 at 7k with WGDC around 60% falling off to 45% after 6k. Since I already had the Prodrive, DW injectors, and AVO pump installed when I put the turbo in I had no reason to "try" the stock BCS. I still question why anyone would, really.

 

It just seems to me that the Prodrive's dynamics enable better WG actuation, period. There is much lower resistance in the WG fill circuit without a pill which leads me to think the Prodrive will be better at capping boost without overshoot, especially during the end of spoolup when larger WGDC have been speced. At least that is how I explain my lack of overshoot . It is also why I used the ID hoses I did, larger for the compressor to the BCS and smaller from the WGA to the BCS.

 

I admit not trying the pill thing with the Prodrive..... along with much further tuning lately. Mother Nature has been having winter fun here for a while now. But I will, just so I know what it does. In a sense it is just like using a smaller pill with the stock BCS, and while I liked some things that did, I did NOT like others.

 

Like I said, all my information comes from just this one car, and my own limited experience tuning. I'm still learning and read these threads hoping to learn more. The reason my WB got permanently installed was because I can never leave the tune alone .

 

The pro-drive will definitely help if you are on the upper end of the WGDC spectrum.

 

On my AVO380 I was only in the 50s or 60s percentage with the OEM EBCS.

 

Having boost control is all about tuning the TD tables. Having something that doesn't need as much WGDC might make it seem like you have more control, but an adjustment of the TD tables would likely do the same thing.

[SeeeeeYa]

The pro-drive will definitely help if you are on the upper end of the WGDC spectrum.

 

On my AVO380 I was only in the 50s or 60s percentage with the OEM EBCS.

 

Having boost control is all about tuning the TD tables. Having something that doesn't need as much WGDC might make it seem like you have more control, but an adjustment of the TD tables would likely do the same thing.

 

 

Would you give an example, please?

 

Although my 'tune' has what seems to me to be great boost control, i.e., hitting target and holding it with zero overboost, in 3rd through 5th, I can criticize it only in that I'd prefer full boost to hit a tad earlier. And maybe more of all of it in first and second. On the other hand the numbers suggest that it is working well in that area.

 

I have always been under the ...illusion?.. that it was WGDC that defined boost level and TD that defined how one got to and/or held that level.

 

While I have more success tuning boost now after the exposure of the boost control system's PID roots, it is not devoid of mystery yet. But sometimes I wonder if there isn't a place of diminishing returns. What with my car working well subjectively and producing good logging numbers, how much more can be safely and reasonably extracted before I begin to believe my wife is right, and I am obsessing . (I always answer, "I just want it safe!" But I really mean, "I want all of it!!.")

 

So I am serious, give some example where I can use TD to enable me faster spool and more boost in first and second with lower WGDC, and without touching my first priorities of a) hitting target with zero overboost, b)holding target firm without oscillation, c) zero difference between those actions in any gear.

[mickeyd2005]

I'm hitting target boost with WGDC in the low 40% with stock BCS and 1.0 mm restrictor pill.

 

Sure the prodrive is more sensitive and responds faster but that's why most people who tune 3 port BCS will use 1/2 the slope for the TD tables to reduce the sensitivity. You end up having to tune in the response rate that you need.

 

For example, let's say the closed loop range for hitting boost is 40% to 47% with the prodrive. An equivalent 2 port BCS will have an equivalent range of say 40 to 54%. We would then adjust the TD tables and TD ranges to accommodate both. Tune ends up providing the same level of performance. The internal ecu numbers are just different.

[Infamous1]

Remember we are still blocking with the Prodrive vs bleeding with the stock BCS. No matter what size the pill the Prodrive after dialed in should be more stable and consistant. Just seems it is quite a bit harder to dial in.

[mickeyd2005]

But you never run 100% blocked. No one runs 100% WGDC. Typically people run 40-70%. Under steady state conditions, it's all the same.

 

In fact without the pill, you are more unstable with the prodrive because small changes to the WGDC will allow the pressure to build or dump in the actuator quickly. That's why people cut the turbodynamics in half.

[mickeyd2005]

I think this is why when LBGT added a large diameter pill, 1.25 mm, to his 3 port system, it stabilized his boost. I believe his boost problem is a mechanical problem, but the smaller pill helped to stabilize it.

[Infamous1]

But you never run 100% blocked. No one runs 100% WGDC. Typically people run 40-70%. Under steady state conditions, it's all the same.

 

In fact without the pill, you are more unstable with the prodrive because small changes to the WGDC will allow the pressure to build or dump in the actuator quickly. That's why people cut the turbodynamics in half.

True I could see that, I maybe should do some testing with different pill sizes on the factory BCS. Just for kicks...

[mickeyd2005]

BTW, if you are running meth, you should run a 3 port BCS with no pill.

 

At 0% WGDC, a restrictor pill will still allow boost to build higher.

[SeeeeeYa]

I do run meth and run my 3-port Prodrive sans pill.... so far. And dialing in the Prodrive did take a bit of adjusting. The 1.25mm pill is the stock LGT pill that LBGT used, although I thought he did this on low boost. If there are new and improved results on a normal map for his 380 using a pill please share them.

 

I did have to modify the TD numbers considerably, starting with simply cutting everything, almost, in half as said. But with the generous help of a couple of posters here I am probably more pleased with my boost control than any other part of my evolving tune. It is stable, ramps up consistently to full boost around 3600-3700, does not overshoot and holds target from then on, usually without any fluctuation at all.

 

At first I thought I was going to have a problem with boost creep up at redline, but by reducing WGDC way down it is fine. That's one of the reasons I maintain the Prodrive is so good, it may take some adjustment of the WGDC to get the results you want but they are there when you do. After a couple of months changing out pills on the bleed-type stock BCS it always ended up with some tweaky compromised somewhere. Solving one issue brought another. With the Prodrive I seem to have no compromises.

 

I would like, however, full boost a little earlier. Right now I'm looking elsewhere, AVCS and early fuel, for example. But again, I wonder if I am not obsessing since logging reveals great numbers (to me ). Every nut and bolt, every moment of work and tuning is my own. I'm sure PDX, e.g., would blow my tune away, but part of the satisfaction I get from all this hoopla is the thrill of development. I'm not so sure having what would be the certain and absolute FINAL evolved setup and tune would make me happy. I might get bored .

[05pearl]

BTW, if you are running meth, you should run a 3 port BCS with no pill.

 

At 0% WGDC, a restrictor pill will still allow boost to build higher.

 

Forgive my ignorance, but why would the use of meth require a 3 port as opposed to the stock BCS? EDIT - or are you simply saying that if one uses meth and a 3-port then they should use no pill?

[mickeyd2005]

I'm not a meth expert but the systems that I have seen disable boost control as a failsafe. In other words WGDC = 0 for failsafe.

 

At WGDC = 0, it doesn't matter if you have 3 port or 2 port. The pathway to the inlet is closed.

 

What does matter if there is blockage (pill) between the compressor housing and the actuator.

 

Let's say you set the actuator spring at 10 psi, you'll see the boost slope change at 10 psi. If there is no pill in there, the boost should be flat after 10 psi. If there is a small diameter pill, you'll see the boost creep upwards in the mid-rpm range. For a failsafe, that might not be desireable. So, for meth failsafe, it would be best to not have a restrictor pill in the system. That's only possible with a 3 port.

[LittleBlueGT]

I do run meth and run my 3-port Prodrive sans pill.... so far. And dialing in the Prodrive did take a bit of adjusting. The 1.25mm pill is the stock LGT pill that LBGT used, although I thought he did this on low boost. If there are new and improved results on a normal map for his 380 using a pill please share them.

 

I did have to modify the TD numbers considerably, starting with simply cutting everything, almost, in half as said. But with the generous help of a couple of posters here I am probably more pleased with my boost control than any other part of my evolving tune. It is stable, ramps up consistently to full boost around 3600-3700, does not overshoot and holds target from then on, usually without any fluctuation at all.

 

At first I thought I was going to have a problem with boost creep up at redline, but by reducing WGDC way down it is fine. That's one of the reasons I maintain the Prodrive is so good, it may take some adjustment of the WGDC to get the results you want but they are there when you do. After a couple of months changing out pills on the bleed-type stock BCS it always ended up with some tweaky compromised somewhere. Solving one issue brought another. With the Prodrive I seem to have no compromises.

 

I would like, however, full boost a little earlier. Right now I'm looking elsewhere, AVCS and early fuel, for example. But again, I wonder if I am not obsessing since logging reveals great numbers (to me ). Every nut and bolt, every moment of work and tuning is my own. I'm sure PDX, e.g., would blow my tune away, but part of the satisfaction I get from all this hoopla is the thrill of development. I'm not so sure having what would be the certain and absolute FINAL evolved setup and tune would make me happy. I might get bored .

 

pm sent

[05pearl]

I'm not a meth expert but the systems that I have seen disable boost control as a failsafe. In other words WGDC = 0 for failsafe.

 

At WGDC = 0, it doesn't matter if you have 3 port or 2 port. The pathway to the inlet is closed.

 

What does matter if there is blockage (pill) between the compressor housing and the actuator.

 

Let's say you set the actuator spring at 10 psi, you'll see the boost slope change at 10 psi. If there is no pill in there, the boost should be flat after 10 psi. If there is a small diameter pill, you'll see the boost creep upwards in the mid-rpm range. For a failsafe, that might not be desireable. So, for meth failsafe, it would be best to not have a restrictor pill in the system. That's only possible with a 3 port.

 

I see now. Thanks for the explanation. Maybe that is why I saw about 12-13psi instead of 10psi boost when testing my WI failsafe.